1. Field of the Invention
The present invention relates to photoluminescence road marking materials and road structures. More particularly, the present invention pertains to a novel photoluminescence road marking material which is useful for a marking of a lane of a road and the like, has a high photoluminescence performance and can find an application in a white line, or a color line of, for example, yellow, orange or any other appropriate color by suppressing a green color tone regardless of concurrently using a photoluminescence pigment, and a road structure comprising the novel photoluminescence material.
2. Description of the Related Art
Heretofore, a photoluminescence pigment which absorbs and stores light energy of sunlight or an electric light and, then, emits the energy outside as light has well been known. An application of the pigment for a road marking by making use of excellent characteristics thereof that visual recognition can be obtained at nighttime or in a dark place has been proposed. For example, JP-A-10-82023 proposes a photoluminescence road marking material in which a transparent or semi-transparent light scattering layer is provided on a white or yellow base layer and, further, a transparent or semi-transparent phosphorescent layer containing a phosphorescent pigment is provided on the light scattering layer.
However, the photoluminescence road marking material, which has conventionally been known, has in common a photoluminescence performance effective for a short time period whereby it is difficult to realize visual recognition, which is held over an extended time period. Moreover, the road marking material emits light not only at night but also at daytime by being compounded with the phosphorescent pigment whereby, for example, a color tone of a lane marking applied on a surface of a road is tinted with green; therefore, there has been a problem that the road marking material can not be used for a lane marking of white. Further, there has been a drawback that, when a pigment is compounded into the road marking material for allowing it to be in a color tone of white, yellow, orange or any other appropriate color, a phosphorescent performance is decreased to thereby deteriorate the phosphorescent performance.
Specifically, take, for example, a case of the marking material described in JP-A-10-82023. When a compound which has been recited therein as being preferable was aimed to be reproduced, the photoluminescence property was low, and the color was densely tinted with green by the phosphorescent pigment whereupon it is an actual situation that the compound can not be used for a lane marking of white.
Further, in a case of the conventional marking material, though it is applied on a surface of a road, non-slip performance has rarely been paid attention to; hence, prevention of slip which is derived from wetting with water or staining with oil has been a big problem for the road marking material using the photoluminescence performance.
Under these circumstances, it is an object of the present invention to solve such conventional problems as described above and to provide a novel photoluminescence road marking material which is useful for a marking of a lane of a road, has a required wear resistance or weather resistance as well as a high photoluminescence performance and can find an application in not only a white line, but also various types of color lines by suppressing a green color tone and can, further, be imparted with a non-slip performance.